Transformer winding retainer



Jan. 1, 1957 D. H. HARSE TRANSFORMER WINDING RETAINER Filed April 5, 1955 ilu E. S Y ..D..\. E RA M N OH. /R .MH .m VMM- A m G s m D. 5 2 2 7m @U 3 3 w v1 m B5 I57 1 4 5mm 6. l |l 2 6 n "1 u 62 3 3 2 2 G n@ F n 2. d 8 a. mw C..

United States Patent TRANSFRRER WINDNG RETAINER Douglas H. Harse, North Syracuse, N. Y., assigner to General Electric Company, a corporation of New York Application April 5, 1955, Serial No. 499,410

1 Claim. (Cl. 336-198) This invention relates to a new and improved device for supporting windings on high voltage cored transformers particularly where it is desired to induce a voltage in such a winding but at the same time to avoid actual contact with the core.

ln television line scanning circuits it is a common practice to employ a sweep transformer of the core type which not only includes the usual windings for energizing the defection and accelerating elements of the picture tube, but also one or more auxiliary windings, usually of one or two turns, for energizing filament heating circuits and the like. These transformers operate at high electrical potentials and if the filament winding should actually come in contact with the core, an insulation breakdown may result. Further, a television receiver is subjected to movement, as during manufacture, transportation and servicing. Consequently, unless special supporting and retaining means for the auxiliary windings are provided, they may become displaced and/ or deformed and their operability impaired.

Various attempts have been made to position and hold the filament Winding on the core of such a transformer. These prior attempts have involved the utilization of rigid supports of ceramic and plastic paper insulating materials mounted on a core portion to hold the wire. These devices have required the use of some kind of fastening or securing means to position the filament holder and increase the cost and the number of steps required in the assembly of such a transformer. The home television receiver is usually produced by using mass production techniques and is provided with a high voltage transformer having a core formed out of two U-shaped sections wherein the legs of the U abut each other so that they form a generally rectangular structure. The provision of a filament winding retainer which could be inserted over one of these legs prior or subsequent to the assembly of the two legs and which is capable of being secured by the winding itself would greatly diminish the cost of such a device and the complexity of the entire assembly.

Therefore, it is an object of my invention to provide an improved transformer winding retainer which is simple in its construction and easy to assemble to the transformer core.

It is another object of my invention to provide an improved transformer filament winding retainer which will hold the windings securely in the desired position and will not occupy an excessive amount of the limited space available.

It is still another object of my invention to provide an improved filament winding retainer which is capable of supporting the filament windings for at least several heater circuits each in its proper position and separated from the other.

Briefly stated, in accordance with one aspect of my invention, I provide a retainer formed from a relatively thin flexible insulating material. The retainer may be Patented Jan. 1, 1957 punched or cut out of the material and then bent into a substantially tubular conformation to encompass one of the core legs prior or subsequent to the assembly of the two core sections and into which the other core leg may be inserted during assembly. A plurality of openings in the extremities of the retainer are provided, so that the winding leads may be threaded therethrough to hold the retainer in its proper position on the core legs.

The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claim. My invention itself, however, both as to its structure and the manner of assembly, together with further objects and attendant advantages, may be best understood by reference to the following description taken in connection with the accompanying drawing in which:

Figure l is a plan view of my Winding lead retainer prior to its being assembled on a transformer core;

Figure 2 is a front view of an assembled transformer with my winding lead retainer mounted on the core and supporting the leads grouped around the core leg; and

Figure 3 is a view Similar to Figure 1 showing another form my invention may take to accommodate windings for more than one filament heating circuit.

Referring now to Figure l, there is shown a winding lead retainer which has been formed from a relatively thin flexible sheet of insulating material. A material suitable for this purpose is known as fish paper and is commonly used throughout the electrical industry. The retainer is designated generally by the reference numeral l. It comprises a relatively long central or body portion 2 and a pair of shorter end portions or extensions 3 and 4 formed integrally with the central portion 2. Formed in extensions 3 and 4 are means for retaining the winding such as elongated slots or openings 5 and 6. These slots receive the winding leads in a manner to be brought out in greater detail hereinafter. Cutout portions or elongated notches 7' and 8 are provided in the central portion 2, the notch 8 providing shoulders 9 and the notch '7 providing shoulders 10 to limit the movement of the retainer on the transformer core, as will be de scribed below.

Referring now to Figure 2, there is shown a transformer assembly having a core comprised by a pair of generally U-shaped core sections 20, 2 which are positioned in opposed relation so as to define a generally rectangular window 22 therebetween. The cores may be compounded of any suitable magnetic material such as ferrite or powderd iron. The usual principal windings 23 and 24 are supported on the upper legs of the core sections. The whole assembly is clamped between insulating side panels 25 in any suitable manner. The arrangement shown is for purposes of illustration only and the shape and design details of the core, transformer and mounting assembly may take any form found to be convenient and desirable. Since the details of the transformer core and mounting construction form no part of the present invention, connecting leads and terminals at the principal windings have been omitted from Figure 2 to simplify the drawing.

Mounted on the legs of the U-shaped sections of the transformer described in the immediately preceding paragraph, opposite from those legs on which the principal windings are mounted is my winding lead retainer l. Since, as pointed out above, the retainer is formed from a flexible insulating material, it may easily be bent around the legs to assume a generally tubular shape. In this position, the extensions 3 and 4 extend laterally out from the legs and are in contact, or substantial contact, with each other at their extremities.

As shown in -Figure 2, a winding 26 suitable for connection to a tilament heating circuit has been looped around the outer surface of the retainer i. One end 26' of the winding 26 has been threaded rst through the opening 6 and then the opening 5. The other end 26 of the winding has been threaded rst through the opening and the opening 6. if desired, a fastening or retaining element such as shown at 27 may be placed over the two leads from the winding to retain the winding and the support l in their proper assembled position. The retaining element is not necessary if an insulated filament winding is used which, because of the wire diameter and insulation, is of suflicient iniexibility to remain in a xed position. l'n this situation, threading the winding through the slots 5 and 6 will hold the retainer in its assembled position.

It can be seen in Fig. 2, that when a filament windv ing retainer, proportioned generally as illustrated in Figure 1, is mounted on the core legs, it assumes a position where the extensions 3 and 4 depend below the legs. ln this position the shoulders Si and l@ do not engage the vertical extensions of the core sections 2t?, 2l and the retainer is capable of some rotation relative to the core legs. Excessive rotation of the retainers l could either deform the winding leads or bring them in proximity to the high voltage windings 23 and 24. in order to prevent this, the shoulders 9 and 155, prior to such excessive rotation of the retainer, will Contact the vertical extensions of the core sections 2@ and 251. Furthermore, transverse movement of the retainer is undesired, because the transformer, when assembled in a television chassis, has a fixed relationship to the other components such as the rectier whose heating circuit is supplied by the winding 26. For this reason, the length of the retainer body portion 2 between the notches 7 and S is such that the retainer contacts, or almost contacts, the vertical extensions of the core sections thereby preventing or limiting the transverse movement of the retainer l. It may be found convenient to position the retainer and support so that the extensions 3 and 4 project at an angle to the longitudinal plane of the transformer. This may be accomplished by shortening the notches 7 and 3 and placing them on either side of transverse centerline of the retainer l as desired. Thus, a large degree of retainer rotation may be obtained or limited rotation and/or selective positioning is possible depending on the length and location of the notches 7 and 8.

The manner of assembling the retainer on the core legs is not to be considered to be limited to wrapping it around the legs after they have been `ioined together by their supporting brackets or securing means. it may be desired to wrap the retainer l and winding lead 26 around the leg of one core section prior to its assembly with the other section and the second section The retainer embodying my invention provides an improved assembly particularly adapted for supporting one or more turns of transformer windings in spaced relation about one core leg of the transformer so that air insulation is provided between thes windings, the transformer core members, and other transformer windings. This reduces the danger of insulation breakdowns and makes it possible to cover the auxiliary windings with an insulating material of less critical breakdown properties than would otherwise be required. Furthermore, the assembly itself is made a much more simple operation and the cost of the insulating material supporting the windings is considerably reduced.

Another form which my invention may take is illustrated in Figure 3 of the drawing wherein like components have been indicated by the same reference numeral. in this form of the invention, the end portions or extensions 3 and Li are provided with a step-like construction at their extremities and matched sets of openings 5 5 and 6-6 are provided at each level of the step openings. In this form of the invention it is possible to provide a retainer and support for the windings of one or more filament heating circuits and to space them a suitable distance from each other so that mechanical or electrical interference will be minimized.

it will be seen that l have provided a winding supporting and retaining assembly that can be readily assembled and disassembled and which can be readily adapted for use with many types of transformers as well as with the speciiic type shown with the above described forms of my invention.

While the present invention has been described by reference to particular embodiments thereof, it will be understood that numerous modications may be made by those skilled in the art without actually departing from the invention. l, therefore, aim in the appended claim to cover all such equivalent variations as come within the true spirit and scope of the foregoing disclosure.

What I claim as new and desire to secure by Letters Patent of the United States is:

A transformer assembly comprising a four-legged core of rectangular configuration having a rectangular window, a sheet of flexible electrical insulating material having a body portion, means dening openings near opposite ends of said body portion of said sheet of material, projections on said body portion of said sheet of material extending in directions that are transverse to a line between said openings, said sheet of material being wrapped around one leg of said core, a winding wrapped around said sheet of material and extending lthrough said openings so as to hold said sheet of material around said leg of said core, the width of said body portion being less than the width of said window along the legs of said core about which said sheet of material is wrapped, the length of said projections and the width of said body portion being greater than the width of said window in the direction of the leg of the core around which said sheet of material is wrapped.

References Cited inthe iile of this patent UNTTED STATES PATENTS 2,500,766 Obert et al Mar. 14, 1950 2,612,545 Gray sept. 3o, 1952 2,665,393 Bocciarelli ian. 5, 1954 2,702,888 Harse Feb. 22, 1955 .4 kin* 

